Improvement in devices for bending tube-skelps



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s.,P'. m. TASKER. Devices for Bending Tub-Skelps.

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S. P M. TASKER.

- Devices for Bending Tube-Skglps.

i 94 157 553, P ate nted Dec.8,l87 1.

THE GRAPHIC CQENQTO'IJTNJSI: H PARK FLAI EEJLY UNITED STATES PATENT Orrrcn.

STEPHEN P. M. TASKER, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT lN DEVICES FOR BENDING TUBE-SKELPS.

Specification forming part of Letters Patent No. 157,653, dated December 8, 1874; application filed October 17, 1874. V

. CASE A.

To all whom it may concern: I

Be it known that I, STEPHEN P. M. TAsKnn, of the city and county of Philadelphia, in the State of Pennsylvania, have invented a Die and Mandrel for Manufacturing Metal Tubes, of which the following is a specification:

My invention consists in the combination of a mandrel of peculiar form with a continuous die, having a bell-shaped mouth, through which a U-shaped skelp is conducted to the die, as hereinaiter more fully described.

The front end of the die, at its connection with the guide, is of U shape, and gradually assumes a circular shape to its extreme end, the upper portion being cut away for the free passage of the edges of the skelp, to prevent their being chilled by contact with the cold metal, whereby the edges are kept hot for the welding process.

For making lap-welded tubes, one side of the die inclines toward the center less than the other, so as to cause the skelp at that side to overlap the other edge for welding; but for butt-joint tubes the two sides of the die are equal.

The mandrel is connected, at its front end, with a guide that is fast to the upper side of the die. This guide is rounded and beveled each way at its front end, so that, if the edges of the skelp should be forced too far inward, they will be turned to their proper positions without injury. to the skelp. The mandrel has a stem on its front end, which fits in a hole in the guide, and is held there by a detachable pin, so as to be readily removed from or connected with the guide.

The mandrel, from the stem, gradually increases in size to the internal diameter of the tube. The upper part, however, is removed to admit of the free bending of the skelp, and the corners are rounded to prevent the edges of the skelp being cooled by coming in contact with the cold metal.

At the outer end of the mandrel, a short distance from the end of the die, it assumes a complete round form, so that, by combining suitable grooved rolls therewith, the edges of the skelp for either lap or butt joints may be 7 welded as the tube passes from the die.

In the accompanying drawings, Figure l is a longitudinal section of the die A and mandrel B. Fig. 2 is a cross-section at the line a b of Fig. 1, the lap-welded skelp 2 being in position. Fig. 3 is a like section at the line 0 d. Fig. 4: is a cross-section of the mandrel B, at the line 0 f, looking on the end of the die A. Fig. 5, Sheet No.2, is a cross-section like Fig. 4, with the exception that it is formed for a butt-joint tube. Fig. 6 is a front view of the die and mandrel.

Like letters of reference in all the figures indicate the same parts.

A is a die of such configuration as I use for bending lap-welded tubes. It has abell-shaped guide, a, for conducting a Ushaped skelp. B is the mandrel, connected with the internal guide 0 by means of the opening I) of the guide and the projecting stem 0 of the mandrel, which fits therein. The mandrel is held firmly in position by means of the pin D, (shown clearly in Figs. 1 and 2.) The pin D has a projecting part, by which it is withdrawn when the mandrel has to be removed. At the commencement of the die, at the line a b, it is of U shape. The vertical sides are gradually contracted to bring the edges of the skelp 2 into circular shape for welding, the die being in the form represented in Fig. 3. At the line 6 f, at the end of the die, it has assumed the form represented in Fig. 4. The curve (1 at the side of the die is farther removed from the center than the curve d, so that, as the bending down of the edges e and. e of the skelp is completed, the edge 6 shall overlap the edge e for welding; but for butt-joint tubes the curves are equal, as seen in Fig. 5. From one end of the die to the other the upper portion is cut away, forming a recess, f, to admit of the free passage of the edges of the skelp, to prevent their coming in contact with the cold metal, whereby they are kept in a heated state for the weld ing process, as hereinafter described. The front end of the guide 0 is rounded and beveled each way, as seen in Fig. 6, so that, if the edges of the skelp should be forced too far inward, they will be gradually turned], as they strike against the guide, outward against the die A without injuring the skelp. The lower edge of the guide has a circular form, corresponding to that of the mandrel, and is rounded off at the end to insure an easy passage of the skelp. From the stem of the mandrel B it is swelled out to the size of the inner diameter of the tube, as seen in Fig. 1, to react against the pressure of the die A. The upper side of the mandrel is cut away, and the corners rounded off, to prevent the edges of the skelp. being cooled by coming in contact with the cold metal. The outer end of the mandrel, a short distance from the end of the die, assumes a full rounded form, B, the size of the inner diameter of the tube, to be used in combination with grooved rolls geared together, which Weld the joint as it passes through the rolls, any suitable guide being used for conducting the skelp to the rolls.

I claim as my invention-.

1. The improved skelp-bending die A, comprising the funnel-shaped portion a, the cylindrical part with enlargement f at top, and the guide G, as set forth.

2. The detachable mandrel B, With or without the swell in the middle, in combination with the die A and guide 0, the mandrel being held in connection with the guide by means of the pin D, substantially as described.

3. The combination, with the die A, of the mandrel B, having a circular form at its lower side for. shaping the skelp, and a relieved portion with rounded corners at its upper side to prevent the edges of the skelpbeing cooled by coming in contact with the cold metal, substantially as and for the purpose specified.

STEPHEN P. M. TASKER.

Witnesses:

THOMAS J. BEWLEY, STEPHEN USTICK. 

